The present invention relates to a device which can be used to separate from each other a plurality of similar articles which are adjacent to each other.
More particularly, the present invention relates to a device which is particularly suitable for separating from each other the rolls of a series or plurality of rolls of wound-up webmaterial, for example of the type produced by what is known as a rewinding and cutting machine, or rolls of cardboard produced by a cutting machine, rolls of printing paper, rolls of adhesive tape or other.
In the paper converting industry use is made of machines for producing rolls of paper material, for example rolls of toilet paper of relatively large diameter, usable in dispensers or feeders for communal areas, public premises or similar. These machines unwind the webmaterial from an initial reel having a large axial length, and cut the webmaterial by means of normally rotating cutters located along the path of the advance of the strip, to produce a plurality of bands of webmaterial with a width equal to the axial length of the finished rolls. The individual bands are then wound into a plurality of rolls which are axially aligned with each other and which must then be sent individually to the packaging machines.
Machines of this type are produced by the applicant and marketed under the trade name of xe2x80x9cRodina 57.00xe2x80x9d and xe2x80x9cRodumat 58.00xe2x80x9d. Similar machines are produced, for example, by Jageneberg of Germany, and marketed under the name xe2x80x9cVari-Durxe2x80x9d.
One of the problems found in these machines is due to the fact that the bands of webmaterial tend to deviate in the area between the cutting and the winding, thus causing a partial overlapping and consequent interconnection of adjacent rolls caused by the partial penetration of the turns of one roil into those of the adjacent rolls. This causes problems in the subsequent packaging stages, since interconnected rolls cannot be packaged.
Similar problems occur, for example, in machines called cutting machines for producing rolls of cardboard from strips of cardboard of greater length, or in machines for producing paper rolls for calculating machines or other office machines. Similar requirements may also arise in the adhesive tape industry, where the rolls of adhesive tape are produced by longitudinal cutting and rewinding from reels of large axial length.
For separating rolls of paper material from each other, there are existing devices with rotating blades which act in a direction orthogonal to the advance of the rolls. These devices are not versatile and have considerable disadvantages in operation.
The object of the present invention is to provide a device which can be used to avoid the problems occurring at the packaging stage and which can be used to separate efficiently from each other the rolls produced by a rewinding and cutting machine or other similar machine.
More generally, the object of the present invention is to provide a device which can be used to separate efficiently from each other two or more similar articles which are adjacent to each other and may be partially adhering to each other.
These and other objects and advantages, which will be clearly understood by those skilled in the art from the reading of the following text, are essentially achieved by means of a device for separating from each other a plurality of objects which are adjacent to each other and are being fed in a direction of advance along an advance path, comprising a member which is rotatable about an axis of rotation and is positioned, with respect to the direction of advance, in such a way that it interferes with the articles fed along said advance path, the peripheral velocity of said rotatable member at the point of contact between said member and said articles having a component substantially matching the direction of advance of the articles.
The rotatable member strikes the areas of the individual articles approximately opposite the areas with which they rest on the advance path, in such a way as to force the individual articles to detach themselves from each other and also, if necessary, to tilt. The lower support terminates upstream of the point at which the rotatable member acts on the individual articles. The detachment is the result of a combined action of the thrust of the rotatable member and the end of the lower support. A device of this type is particularly advantageous if it is located at the discharge end of a rewinding and cutting machine or other machine capable of simultaneously producing series of rolls of wound-up webmaterial, from individual bands of material which are fed in parallel paths. Preferably, the axis of rotation of the rotatable member is orthogonal to the direction of advance of the articles.
In a particularly advantageous embodiment of the invention, the rotatable member comprises a wheel carrying a plurality of rollers arranged with their axes parallel to the axis of rotation of the wheel and positioned around a circumference whose center is on the axis of the wheel. The individual rollers strike adjacent articles which are advancing along the advance path, to push them apart from each other. The surface of the rollers may advantageously be shaped to match the shape of the articles. In the case of rolls of webmaterial, it is advantageous for the rollers to have a concave profile, and for the axial cross-section of the profile to have a radius of curvature equal to or slightly greater than the radius of curvature of the rolls. In the case of a device suitable for operating on rolls of variable diameter, the profile of the curve defining the outer surface of the concave roller may be equal to or greater than the maximum radius of the rolls to be handled.
In a particularly advantageous embodiment of the present invention, the rollers are supported so that they are free-running on said wheel. One result of this is to avoid the risk of damaging the articles on which the rollers act. This is particularly useful in the case of articles consisting of rolls of paper, for example tissue paper, such as rolls of toilet paper or similar products.
The rollers are preferably individually removable from the rotatable member. Additionally, this member is rotated by an actuator which allows the rotation speed to be modified (at least within certain limits). In this way it is possible to match the device to articles of various sizes. In the case of rolls of wound-up webmaterial, it is possible to arrange for each roll to be struck at least once by the rotatable member, in other words by one of the rollers supported by the aforesaid wheel. This is achieved by removing some of the rollers, if necessary, when the axial dimension of the rolls increases and/or by modifying the rotation speed.
It is advantageous to arrange for the rotary movement of the rotatable member to be in phase with the movement of displacement of the individual articles along the advance path, in such a way that each article always receives a thrust at the same point. This may be achieved by means of a suitable mechanical drive and timing members included in it. Alternatively, and preferably, the timing may be provided electronically by a control unit which controls two motors, one for the rotation of the rotatable member and the other for the advance of the articles.
In general, for optimal operation, the speed of rotation of the rotatable member is such that, in the area in which the impact with the articles to be separated takes place, the rotatable member has a peripheral velocity of, for example, 1.5 or 2 times the speed of advance of the articles.
The advance path may be defined by a conveyer of the belt or other type, on which the individual articles rest. However, in a particularly advantageous embodiment, the advance path of the articles is defined by a guide along which said articles are pushed by a pusher. The rotatable member is located above said guide.
Further possible advantageous characteristics of the invention are indicated in the attached dependent claims and described with reference to an example of an embodiment.
With the device according to the present invention, it is a simple matter to modify the direction and amount of the thrust exerted on the individual articles. The device can also be adapted easily to different sizes of the articles to be handled.